Amazon has announced today that publishers and authors will receive a much larger royalty for books sold in the Kindle Digital format beginning on June 30th.

Currently, the royalty rate is 30 percent, but that will soon balloon to 70 percent.

The move is being seen as a chance for Amazon to preemptively attack Apple's upcoming tablet device, which is likely to have an e-book deal with HarperCollins right from launch.

Amazon will exclude delivery costs from the royalties paid, and each megabyte is 15 cents. To qualify for the higher royalty rate, your book must be priced between $2.99 and $9.99 and be selling in the U.S. Public domain books from before 1923 do not qualify.

Physical books normally net authors about 7 to 15 percent of prices set by publishers and 25 percent for digital books, meaning Amazon's latest move should make authors very happy to have their works available digitally.